The present disclosure relates to a multilayer electronic component and a method of manufacturing the same, and more particularly, to a multilayer electronic component having excellent magnetic properties and improved strength, and a method of manufacturing the same.
Among electronic components, inductors, important passive devices for configuring electronic circuits, together with resistors and capacitors, are used to remove noise or as components configuring LC resonance circuits, and the like.
Passive devices such as power inductors, and the like, used in smartphones, mobile information technology (IT) devices, and the like, operate in a relatively high frequency band of 1 MHz or above. Therefore, a soft magnetic material prepared by mixing, calcining, and grinding a plurality of metal oxides known as soft magnetic ferrites, for example, Fe2O3, NiO, CuO, ZnO, or the like, has commonly been used.
However, recently, with increasing use of smartphones, mobile IT devices, and the like, data transmission amounts have increased significantly, switching frequencies of central processing units (CPU) have increased to allow for high speed data processing, and power usage amounts in mobile devices, and the like, have rapidly increased due to smartphone screens having relatively large areas, high resolutions, and the like. Due to the increase in power usage in the mobile devices, passive devices such as power inductors, and the like, injected in plural, in a driving circuit design such as that of CPUs, display units, power management modules, and the like, should have high power consumption efficiency.
According to demands for improving the efficiency of power inductors, and the like, as described above, power inductors capable of operating in a high frequency band of 1 MHz or above by replacing a soft magnetic ferrite material with a fine metal powder and having improved energy consumption efficiency and direct current bias properties by significantly decreasing eddy current loss, or the like, have been produced as products.
According to the related art, as an inductor to which metal powder is applied, there exist thin film inductors and winding inductors.
The thin film inductor is manufactured by winding copper wire on a board such as a printed circuit board (PCB), or the like, through a plating method, by press-molding a metal-epoxy mixed material in which metal powder and an epoxy resin are mixed with each other so as to enclose the copper wire, and performing a curing process on the epoxy resin by heat-treatment.
The winding inductor is manufactured by winding a copper wire, sealing the wound copper wire using a composite material in which a metal and an epoxy are mixed with each other, press-molding the sealed copper wire in a mold at a high pressure to obtain a chip, and then curing the epoxy by heat-treatment.
The inductors manufactured by two methods as described above have significantly excellent DC bias properties as compared to a ferrite multilayer inductor, and as a result obtained by evaluating properties of a power management integrated circuit (PMIC) module set, or the like, efficiency is improved by several percent or more.
As described above, a metal magnetic sheet multilayer inductor has been studied in order to simultaneously secure mass production possibility in addition to advantages that the DC bias properties and efficiency of the inductor, or the like, are improved due to the application of metal powder. The metal magnetic sheet multilayer inductor may be manufactured by forming a uniform mixture of metal powder and a polymer as a sheet, instead of an oxide ferrite sheet, and performing a series of processes such as a via hole punching process, an internal conductor printing process, a stacking process, a sintering process, and the like, on the metal magnetic sheet.
In the metal magnetic sheet multilayer inductor, DC bias properties may be exhibited similarly to those in the thin film or winding inductor; however, since a metal material having physical properties of being oxidized at the time of heat-treatment is used, there is a limitation in a sintering temperature condition of a chip. For example, an oxide layer may be formed on a surface of the metal powder during a sintering process of a metal sheet multilayer body, and a production amount of this oxide layer on surfaces of metal particles may be adjusted by controlling a sintering temperature. The oxide layer serves to suppress insulation breakdown from being generated due to electric connections between the metal particles or between the metal particles and internal electrodes and to impart chip strength by generating bonds between metal particle oxide layers.
However, since bonding force between the metal particle oxide layers is relatively weak and a metal particle filling rate is insufficient, it is difficult to secure sufficient chip strength, and thus, chip breakdown, or the like, may be generated at the time of mounting.
A multilayer electronic component manufactured by stacking and sintering a magnetic layer formed of a paste containing a metal magnetic material and a glass ingredient and a conductive pattern is disclosed in Patent Document 1.
However, in the multilayer electronic component disclosed in Patent Document 1, the glass ingredient may be partially concentrated during a heat-treating process, and the addition of the glass ingredient may be problematic in terms of filling the metal magnetic material during a compressing process before heat-treatment. Such disadvantage in the filling of the metal magnetic material may result in a decrease in permeability, or the like, and a limitation in exhibiting inductance properties as an inductor device.